A mechanism with severing near barbed ends and annealing explains structure and dynamics of dendritic actin networks.
A mechanism with severing near barbed ends and annealing explains structure and dynamics of dendritic actin networks.
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DOI：
10.7554/elife.69031
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发表时间：
2022-06-07
期刊：
影响因子：
7.7
通讯作者：
Vavylonis, Dimitrios
中科院分区：
文献类型：
--
作者：
Holz, Danielle;Hall, Aaron R.;Usukura, Eiji;Yamashiro, Sawako;Watanabe, Naoki;Vavylonis, Dimitrios
单分子成像显示，部分肌动蛋白在并入片状伪足中的树突状细丝网络后几秒钟内解体，这表明在倒刺末端附近经常发生不稳定。为了研究网络重塑背后的机制，我们创建了一个随机模型，其中包含聚合、解聚、分支、加帽、去帽、切断、低聚物扩散、退火和去分支。我们发现，丝切断，加强倒刺端附近，可以解释单分子肌动蛋白的寿命分布，如果寡聚体片段重新退火到自由端的速率常数在体外测量。相同的机制导致肌动蛋白网络与测量的细丝、末端和分支浓度一致。这些网络经历结构重塑，导致更长的长丝远离前缘，在+/-35°取向模式。肌动蛋白斑点寿命成像在亚秒分辨率验证频繁拆卸新组装的肌动蛋白。因此，我们提出了一个统一的机制，适合不同的一套基本板状伪足现象。
Single molecule imaging has shown that part of actin disassembles within a few seconds after incorporation into the dendritic filament network in lamellipodia, suggestive of frequent destabilization near barbed ends. To investigate the mechanisms behind network remodeling, we created a stochastic model with polymerization, depolymerization, branching, capping, uncapping, severing, oligomer diffusion, annealing, and debranching. We find that filament severing, enhanced near barbed ends, can explain the single molecule actin lifetime distribution, if oligomer fragments reanneal to free ends with rate constants comparable to in vitro measurements. The same mechanism leads to actin networks consistent with measured filament, end, and branch concentrations. These networks undergo structural remodeling, leading to longer filaments away from the leading edge, at the +/-35° orientation pattern. Imaging of actin speckle lifetimes at sub-second resolution verifies frequent disassembly of newly-assembled actin. We thus propose a unified mechanism that fits a diverse set of basic lamellipodia phenomenology.
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DOI：
10.2183/pjab.86.62
发表时间：
2010
期刊：
Proceedings of the Japan Academy. Series B, Physical and biological sciences
影响因子：
--
作者：
Watanabe N
通讯作者：
Watanabe N
影响因子：
2
作者：
Michalski PJ;Carlsson AE
通讯作者：
Carlsson AE
影响因子：
2
作者：
McMillen LM;Vavylonis D
通讯作者：
Vavylonis D
影响因子：
2
作者：
Smith DB;Liu J
通讯作者：
Liu J